That RH side is so bad you can see the gap between the nut and the arm. I'd bet the hole in the arm is badly worn, and that the ball joint and stud is OK.
Get a big pry bar and pry DOWN on the tie rod while someone else loosens the nut. The reason you want to pry down and not up is because you are trying to hold the stud from spinning, and forcing it down into the arm is the best way to do this. If you have an air gun, prying down while rattling it loose (2-man job ideally) should get it off no problem. With that loader frame on there, finding something for a pry point should not be hard. Finding someone heavy to stand on it with the heel of one boot should also work. Just make sure they hang on to something.